Software which displays lists of data enables an operator such as a database administrator or a database user to scroll through and selectively view vast amounts of data from a manageable interface such as a display control. Specifically, such software enables the operator to view a subset of the displayed data and to input one or more commands, such as a scroll up command or a scroll down command, to the display control, which cause the display control to display a different subset of the displayed data.
To indicate to the operator that such an input is appropriate, the display control may include a scroll bar, scroll arrow, or other suitable indicia. The operator may use an input device such as a mouse, a scroll-wheel, or a keyboard to input the command to scroll to a different subset of the data. Certain display controls may display such scrolling by displaying a new subset of the data items having substantially the same list items as the previously displayed (i.e., pre-scrolled) subset of the data, but with at least one item removed and at least one item added to the subset. In this way, certain display controls sequentially display a plurality of subsets of data to give the operator the impression that he or she is scrolling through a large list of data items.
Certain display controls also enable the operator to modify the size of the display control used to display a list of data items. For example, certain software may enable an operator to select a resize indicator of a list control and indicate a new size for the list control, thus enabling the operator to decide whether the list control should be sized to display 50 list items or 5 list items. This determination may be limited based on one or more physical limitations of the hardware executing the display control, such as monitor or display size and/or processor speed. So long as the operator is within the hardware constraints of the system, such display controls enable the operator to customize the control to simultaneously display a useful quantity of data. For example, the operator may determine that simultaneously viewing 50 data items is useful when a list includes thousands of data items, and may decide that simultaneously viewing only 5 data items is useful for a list having fewer than one hundred data items.
When such display software is implemented in a network environment, where bandwidth can be at a premium, it is desirable to enable an operator to control the amount of data sent over the networked connection. Thus, certain known software is configured to display a plurality of list data items in a remote display control by operating in either a virtual mode or a non-virtual mode.
Software that is configured to display list data in virtual mode using a remote display control sends only the subset of data needed to fill the display control at a given time. For example, such software may send 50 data items out of thousands of data items to a remote display control sized to display only 50 entries simultaneously. Such software, operating in virtual mode, sends additional data as it is needed, such as based on the operator scrolling through the list, deleting data items for the list, etc. For example, if the operator inputs an up-arrow keystroke, virtual mode software may send data representing the data item immediately above the previously top-positioned data item. It should be appreciated that software configured to operate in virtual mode as described, though minimizing initial bandwidth usage (i.e., only the displayable items are initially sent), requires constant or near-constant network connectivity (i.e., each changed in the displayed set of data requires a small amount of data to be sent).
Software configured to operate in non-virtual mode sends data representing each of the data items upon initialization or creation of the display control. For example, regardless of the size of the display control, if a list includes 200 data items, remote display software operating in non-virtual mode sends all 200 items to the display control. The display control stores the sent data, and internally determines which of the stored data items to display based on operator input. It should thus be appreciated that an operator can scroll through the data items without the display control receiving additional data over the network connection. It should be appreciated that such non-virtual software reduces the need for constant or near-constant network connectivity, but requires substantial initial data throughput to send the entire list of data items upon initialization of the display control.
The software described above requires a software developer to make a determination during coding of whether to implement the software in virtual or non-virtual mode. Thus, such software lacks the flexibility to enable a determination of network capabilities on a remote user by remote user basis. Moreover, such software lacks the ability to determine whether to operate in virtual mode or in non-virtual mode based on the hardware capabilities of the computer system running the display control. The need for the developer to determine whether the software is to operate in virtual mode or non-virtual mode at development time is particularly problematic in the insurance industry, wherein insurance professionals use hardware having vastly differing capabilities to simultaneously access a single remote server.